No. 63398. 



Speaking Arc Lamp. Photophone. 



1059 



63 390. 1 : 4. 



63 397, 63 370. 1 : 8. 



63 398. 1 : 6 



63,389. Microphone with Switch and Eegulating Eesistance 



63.395. Condenser Lens on Stand 



63.396. Water Box for protecting the Selenium Cell from too great a heat 



63.397. Concave Mirror with Selenium Cell, Figure. Price exclusive of battery illustrated 



and of telephone 5. 10. 



s. d. 

 2. 0.0 

 2. 0.0 

 1. 0.0 



63,370. Precision Telephone 1. 0. 



Xos. 50,892 63,395 form the Transmitting Station, and NOB. 63,396, 63,397 and 63,370 the Re- 

 ceiving Station. Tlif source of current can be provided from 15 to 20 accumulators or 20 to 26 dry 

 jells, or other suitable cells in series. 



63,398. Photophonic Transmitting Station for Acetylene Light, Figure, with manometric 

 capsule with sound horn, with pointed burner and interchangeable parabolic reflector; 

 including also Acetylene Generator and short length of rubber tubing ....... 4. 4. 



A small acetylene flame at the focus of the concave mirror is influenced by the sound waves 



striking on the manometer capsule, the variations in intensity of the flame being propagated as a 



parallel bundle of light and being transformed again into sound waves by the secondary station 

 No. 63,397. 



As Receiving Station for above use is made of Nos. 63,397 and 63,370. 



Cl. 5358, 1961, 

 1960. 



67* 



